Analysis of the Total Polyphenol, Flavonoid, and Phenolic Acid Contents in Three Different Leaf Types of Lepidium sativum

Lepidium sativum (LS) is an annual plant that has been used for the treatment of many ailments. The ethanol extracts of pinnately-lobed (PL), pinnately-compound (PC), and pinnately-veined (PV) leaves of LS were examined for their total polyphenol and flavonoid contents, and their phenolic acid (namely caffeic acid (CA), p-coumaric acid (PA), and ferulic acid (FA)) contents were determined using reverse-phase high-performance liquid chromatography-photodiode array (HPLC/PDA) analysis. Among the three leaf types, the highest average total polyphenol content was found in PV (79.87 mg GAE/g extract), whereas PC showed the highest average total flavonoid content (53.35 mg QE/g extract). According to the HPLC/PDA results, PV exhibited a high amount of CA (78.60 µg/g extract) and FA (1,722.85 µg/g extract), whereas a high content of PA (258.72 µg/g extract) was detected in PC. Higher amounts of the phytochemical compounds PV and PC might be indicative of their superior biological activities compared to PL. To the best of our knowledge, this study is the first to quantify and compare the total polyphenol, flavonoid, and phenolic acid contents in three different leaf types of LS.

Incidence, Molecular Characteristics and Pathogenicity of Gibberella fujikuroi Species Complex Associated with Rice Seeds from Asian Countries

Gibberella fujikuroi species complex (GFSC) was isolated from rice (Oryza sativa L.) seed samples from ten Asian countries and investigated for incidence of GFSC, molecular characteristics, and pathogenicity. Regardless of geographic origin, GFSC was detected with incidences ranging from 3% to 80%. Four species, Fusarium fujikuroi, F. concentricum, F. proliferatum, and F. verticillioides, were found to show an association with rice seeds, with F. fujikuroi being the predominant species. In phylogenetic analyses of DNA sequences, no relationship was found between species, isolates, and geographic sources of samples. Unidentified fragments of the beta-tubulin gene were observed in ten isolates of F. fujikuroi and F. verticillioides. With the exception of three isolates of F. fujikuroi, F. fujikuroi, F. proliferatum, and F. verticillioides were found to have FUM1 (the fumonisin biosynthetic gene); however, FUM1 was not found in isolates of F. concentricum. Results of pathogenicity testing showed that all isolates caused reduced germination of rice seed. In addition, F. fujikuroi and F. concentricum caused typical symptoms of bakanae, leaf elongation and chlorosis, whereas F. proliferatum and F. verticillioides only caused stunting of seedlings. These findings provide insight into the characteristics of GFSC associated with rice seeds and might be helpful in development of strategies for management of bakanae.